There’s no good reason for the existence of Asus’s Xonar HDAV 1.3 Slim soundcard, and yet it’s a godsend for those of us who want to hear the high-definition soundtracks on so many of the Hollywood movies released on Blu-ray disc. Blame Microsoft for the contradiction: No one would need a product like this if Vista provided a protected audio path.

After all, this card doesn’t decode Dolby TrueHD or DTS-HD Master Audio soundtracks, nor does it enhance the audio or the video; it just passes the signals through to your A/V receiver. Using the included HDMI cable, the card takes the output from your videocard, re-encrypts the soundtrack so that no one can intercept the bit stream to make a bit-perfect copy, and outputs the encrypted audio and video to a second HDMI port. For those without HDMI, Asus also includes a DVI-to-HDMI cable.

The protected audio path requires a software component, too, so Asus bundles a copy of ArcSoft’s TotalMedia Theatre with the Xonar. Not your favorite media player? Too bad, it’s the only one that’s compatible. For what it’s worth, we don’t have any complaints about the program. There’s nothing objectionable about its user interface; it can handle all the major codecs; and it supports BD-Live, so you can access whatever online content is linked to the movie you’re watching.

Much has been made of the incredible speed advantages PCI Express offers over PCI. Beyond GPUs, however, we haven’t found much worthy of occupying those slots. Asus hopes to change that with its Xonar D2X card—the first soundcard we’ve reviewed that makes use of the PCI Express interface. The D2X is basically a PCI-E version of the Xonar D2 (reviewed April 2008). In our review of the Xonar D2 we lamented the card’s lack of advanced EAX support, something Asus has tried to fix here. But do their workarounds, well, work?

Who’d have thunk it? Long considered a dead zone, soundcards are making a resurgence. Driven by an outcry for audio that doesn’t sound like a box of snap, crackle, pop every time you access your USB ports, manufacturers are releasing new soundcards that surpass the free audio that comes with your motherboard. This month, we test an Auzentech card that uses a Creative Labs chip and Asus’s new entry into PC audio.